It is becoming increasingly common to provide wiring for power distribution in buildings by means of modular or plug-together wiring systems, one such system being described in U.S. Pat. No. 4,146,287. A typical modular wiring system comprises distribution cables having cable connectors on their ends, junction connectors, and tap connectors. The cable connectors can be mated with each other and with the junction connectors when it is desired to provide a power outlet for lighting or other purposes. A tap connector is also mated with each junction connector when an outlet or power source is required so that the tap wires are connected to the distribution wires in the cables.
The economies and convenience which can be realized from the use of modular wiring systems depend in a large part upon the degree of standardization which can be achieved among the connectors and terminals used in the connectors in the system and upon the cost of the connectors. Many existing modular wiring systems require an excessive number of different parts for the system and the need for an excessive number of parts defeats, to some extent at least, the purpose of the system. For example, some systems presently being used require distinctly different types of cable connectors, one type being dimensioned and designed such that it can be mated only with the input side of the junction connector and the other type of cable connector being designed such that it can be mated only with the output side of the junction connector. In some systems, the cable connectors and the junction connector are relatively complex in that they are made up of a molded insulated housing, a metallic shell surrounding the housing, and conductors within the housing which are composed of several parts such as individual terminals crimped onto the ends of stamped feed-through conductors and tap conductors which must be connected by individual crimped connections to the feed-through conductors in the junction connector housing. It would be desirable to reduce the complexity of some of the existing connectors used in modular wiring system without sacrifice of the convenience, safety, and versatility of the system and the present invention is accordingly directed to the achievement of improved junction and tap connectors which are of relatively simple construction.
It is common practice in the manufacture of partition panels for buildings, electrical junction boxes, and fluorescent lighting fixtures, to provide circular holes or circular knock-out plugs of a standard diameter in the parts at locations where wires must pass through the panels. Most of the presently available modular wiring systems have tap connectors, that is connectors for making tap connections to the distribution cables, which are of rectangular cross-section and these tap connectors cannot therefore be conveniently mounted in the circular openings in, for example, an overhead fluorescent lighting fixture. As a result, it is necessary to either provide non-standard openings in the lighting fixture or to use some sort of adaptor between the circular opening in the panel and the rectangular tap connector of the modular wiring system. The present invention in accordance with a further aspect thereof is directed to the achievement of a tap connector comprising a circular housing which can be mounted in a standard circular panel opening and which can also be used with a junction connector having feed-through conductors therein which are in side-by-side parallel relationship, an arrangement which offers the greatest convenience for junction connectors and cable connectors in modular wire systems.
A preferred embodiment of the invention comprises an all plastic junction connector housing assembly having oppositely directed cable connector receiving faces and having side-by-side parallel feed-through conductors therein extending between the cable connector receiving faces. The tap connector comprises a generally cylindrical housing which can be fitted into a circular panel opening of standard dimensions and it has a generally circular mating face which is against a mating face of the junction connector when the two connectors are coupled. The contact terminals in the tap connector are arranged as a non-linear cluster in order that they might all be fitted within the cylindrical housing of the tap connector. Tap connector conductors in the junction connector extend from the feed-through conductors to the tap connector receiving face of the junction connector housing and one or more of these tap conductors extend laterally so that the terminal portions on their ends will also be arranged as a cluster. The tap conductors and the feed-through conductors in the junction connector housing are rigid members which can be easily assembled to the housing and selectively connected to each other to provide the desired tap connections to the distribution conductors in the distribution cables of the system.